panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 91654 99358 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ca8e3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e0a0400,d64,580,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da76328,9,fffffd805e0a0000,0,0,ffff80001d71ceb0) at tcp_usrreq+0xa54 sosend(fffffd805da76328,0,ffff80001d6cdd98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71ceb0,4,ffff80001d6cdd98,0,ffff80001d6cde80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71ceb0,ffff80001d6cde30,ffff80001d6cde80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cdf00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8ed0, count: 5 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic m_copym0: short mbuf chain ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ca8e3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e0a0400,d64,580,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da76328,9,fffffd805e0a0000,0,0,ffff80001d71ceb0) at tcp_usrreq+0xa54 sosend(fffffd805da76328,0,ffff80001d6cdd98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71ceb0,4,ffff80001d6cdd98,0,ffff80001d6cde80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71ceb0,ffff80001d6cde30,ffff80001d6cde80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cdf00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8ed0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6cd860 rbx 0xffff80001d6cd910 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff815e8b5f kprintf+0x15f r9 0x1 r10 0x2 r11 0x4ca1969b84edaa85 r12 0x3000000008 r13 0xffff80001d6cd870 r14 0x100 r15 0x1 rip 0xffffffff81327368 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6cd850 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=91654 stat=onproc flags process=12 proc=0 pri=24, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff80001d71d870,0xffff80001d71c9e0 process=0xffff80001d7063b8 user=0xffff80001d6c8000, vmspace=0xfffffd806bc0abb0 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=1 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 30964 268020 71657 0 2 0 syz-executor.0 30964 465459 71657 0 2 0x4000000 syz-executor.0 39652 472044 14539 0 2 0x2 syz-executor.1 86929 92808 0 0 3 0x14200 bored sosplice 71657 213161 14539 0 2 0x482 syz-executor.0 14539 364941 21047 0 3 0x82 thrsleep syz-fuzzer 14539 392043 21047 0 2 0x4000482 syz-fuzzer 14539 116065 21047 0 3 0x4000082 thrsleep syz-fuzzer 14539 285175 21047 0 3 0x4000082 thrsleep syz-fuzzer 14539 162266 21047 0 2 0x4000002 syz-fuzzer 14539 303778 21047 0 3 0x4000082 thrsleep syz-fuzzer 14539 362856 21047 0 3 0x4000082 thrsleep syz-fuzzer 14539 206219 21047 0 3 0x4000082 thrsleep syz-fuzzer 21047 358614 99358 0 3 0x10008a pause ksh *99358 91654 38527 0 7 0x12 sshd 12776 491557 1 0 3 0x100083 ttyin getty 38527 447009 1 0 3 0x80 select sshd 80764 346903 86688 73 3 0x100090 kqread syslogd 86688 309794 1 0 3 0x100082 netio syslogd 31736 467847 1 77 3 0x100090 poll dhclient 88955 27809 1 0 3 0x80 poll dhclient 46248 5072 0 0 3 0x14200 bored smr 33871 243195 0 0 2 0x14200 zerothread 44596 125210 0 0 3 0x14200 aiodoned aiodoned 9385 1811 0 0 3 0x14200 syncer update 75382 126773 0 0 3 0x14200 cleaner cleaner 34316 148117 0 0 3 0x14200 reaper reaper 59895 372187 0 0 3 0x14200 pgdaemon pagedaemon 93822 466198 0 0 3 0x14200 bored crynlk 27642 60546 0 0 3 0x14200 bored crypto 9460 138949 0 0 3 0x40014200 acpi0 acpi0 31039 134283 0 0 3 0x14200 bored softnet 35015 458464 0 0 3 0x14200 bored systqmp 88038 147121 0 0 3 0x14200 bored systq 375 163889 0 0 2 0x40014200 softclock 15521 45392 0 0 3 0x40014200 idle0 1 403884 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9500 6468K 6724K 78643K 11041 0 pcb 13 8K 8K 78643K 70 0 rtable 113 7K 8K 78643K 454 0 ifaddr 70 15K 15K 78643K 160 0 counters 21 16K 17K 78643K 30 0 ioctlops 0 0K 4K 78643K 70 0 iov 0 0K 28K 78643K 48 0 mount 1 1K 1K 78643K 1 0 vnodes 1220 77K 77K 78643K 1361 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 4 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 1K 78643K 46 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 263 0 sigio 0 0K 0K 78643K 4 0 proc 49 38K 63K 78643K 431 0 subproc 32 2K 2K 78643K 51 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 187 0 in_multi 30 2K 2K 78643K 84 0 ether_multi 1 0K 0K 78643K 10 0 mrt 0 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 225 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 121 39K 39K 78643K 1467 0 UVM aobj 19 2K 2K 78643K 21 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 40 0 NDP 10 0K 0K 78643K 29 0 temp 92 3862K 3927K 78643K 5114 0 kqueue 3 4K 12K 78643K 14 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 8 0 2 1 0 1 1 0 8 0 rtpcb 80 27 0 25 1 0 1 1 0 8 0 rtentry 112 64 0 27 2 0 2 2 0 8 0 unpcb 120 143 0 135 1 0 1 1 0 8 0 syncache 264 8 0 8 2 1 1 1 0 8 1 tcpqe 32 188 0 188 1 1 0 1 0 8 0 tcpcb 544 80 0 76 1 0 1 1 0 8 0 inpcb 296 439 0 432 2 0 2 2 0 8 1 rttmr 72 2 0 1 1 0 1 1 0 8 0 nd6 48 14 0 7 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 0 1 1 0 8 1 pfrktable 1344 66 0 57 1 0 1 1 0 8 0 pftag 88 21 0 16 1 0 1 1 0 8 0 pfstkey 112 2 0 2 1 0 1 1 0 8 1 pfstate 328 1 0 1 1 0 1 1 0 8 1 pfrule 1360 22 0 12 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 271 0 85 15 0 15 15 0 8 1 art_table 32 272 0 85 2 0 2 2 0 8 0 art_node 16 61 0 30 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 0 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 40 0 30 1 0 1 1 0 8 0 shmpl 112 18 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1774 0 374 88 0 88 88 0 8 0 ffsino 240 1774 0 374 83 0 83 83 0 8 0 nchpl 144 2364 0 775 60 0 60 60 0 8 0 uvmvnodes 72 1925 0 0 35 0 35 35 0 8 0 vnodes 208 1925 0 0 102 0 102 102 0 8 0 namei 1024 6344 0 6344 1 0 1 1 0 8 1 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 528 2 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 24 0 18 1 0 1 1 0 8 0 scxspl 192 6815 0 6815 1 0 1 1 0 8 1 plimitpl 152 34 0 27 1 0 1 1 0 8 0 sigapl 424 447 0 418 4 0 4 4 0 8 0 futexpl 56 5009 0 5009 1 0 1 1 0 8 1 knotepl 112 91 0 72 1 0 1 1 0 8 0 kqueuepl 144 38 0 35 1 0 1 1 0 8 0 pipepl 272 114 0 104 1 0 1 1 0 8 0 fdescpl 432 432 0 418 2 0 2 2 0 8 0 filepl 120 2681 0 2586 4 0 4 4 0 8 1 lockfpl 104 63 0 62 1 0 1 1 0 8 0 lockfspl 48 25 0 24 1 0 1 1 0 8 0 sessionpl 112 18 0 8 1 0 1 1 0 8 0 pgrppl 48 18 0 8 1 0 1 1 0 8 0 ucredpl 96 201 0 194 1 0 1 1 0 8 0 zombiepl 144 418 0 418 1 0 1 1 0 8 1 processpl 928 447 0 418 4 0 4 4 0 8 0 procpl 624 729 0 692 4 0 4 4 0 8 1 sosppl 128 3 0 3 1 0 1 1 0 8 1 sockpl 400 611 0 594 3 0 3 3 0 8 1 mcl64k 65536 22 0 22 1 0 1 1 0 8 1 mcl16k 16384 3 0 3 1 0 1 1 0 8 1 mcl12k 12288 7 0 7 1 0 1 1 0 8 1 mcl9k 9216 6 0 6 1 0 1 1 0 8 1 mcl8k 8192 12 0 11 1 0 1 1 0 8 0 mcl4k 4096 26 0 26 2 1 1 1 0 8 1 mcl2k2 2112 2 0 2 1 1 0 1 0 8 0 mcl2k 2048 78596 0 78543 19 10 9 16 0 8 2 mtagpl 96 35 0 6 2 1 1 1 0 8 0 mbufpl 256 126987 0 126817 36 18 18 33 0 8 5 bufpl 280 3829 0 126 265 0 265 265 0 8 0 anonpl 16 59680 0 43912 81 2 79 79 0 107 15 amapchunkpl 152 1947 0 1818 8 2 6 8 0 158 0 amappl16 192 2322 0 1420 58 0 58 58 0 8 12 amappl15 184 104 0 102 1 0 1 1 0 8 0 amappl14 176 27 0 22 1 0 1 1 0 8 0 amappl13 168 34 0 31 1 0 1 1 0 8 0 amappl12 160 4 0 2 2 1 1 1 0 8 0 amappl11 152 53 0 44 1 0 1 1 0 8 0 amappl10 144 84 0 79 1 0 1 1 0 8 0 amappl9 136 375 0 373 1 0 1 1 0 8 0 amappl8 128 354 0 311 2 0 2 2 0 8 0 amappl7 120 194 0 178 1 0 1 1 0 8 0 amappl6 112 24 0 19 1 0 1 1 0 8 0 amappl5 104 358 0 347 1 0 1 1 0 8 0 amappl4 96 434 0 409 1 0 1 1 0 8 0 amappl3 88 117 0 111 1 0 1 1 0 8 0 amappl2 80 2609 0 2543 2 0 2 2 0 8 0 amappl1 72 17696 0 17292 24 15 9 17 0 8 0 amappl 80 966 0 925 1 0 1 1 0 84 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 64 20 0 2 1 0 1 1 0 8 0 uaddrrnd 24 434 0 418 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 434 0 418 1 0 1 1 0 8 0 vmmpekpl 168 6834 0 6800 2 0 2 2 0 8 0 vmmpepl 168 59390 0 57397 125 6 119 120 0 357 32 vmsppl 272 433 0 418 2 0 2 2 0 8 0 pdppl 4096 874 0 838 6 1 5 6 0 8 0 pvpl 32 181347 0 162622 189 2 187 187 0 265 35 pmappl 200 433 0 418 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 271 0 32 8 0 8 8 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ca8e3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e0a0400,d64,580,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da76328,9,fffffd805e0a0000,0,0,ffff80001d71ceb0) at tcp_usrreq+0xa54 sosend(fffffd805da76328,0,ffff80001d6cdd98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71ceb0,4,ffff80001d6cdd98,0,ffff80001d6cde80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71ceb0,ffff80001d6cde30,ffff80001d6cde80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cdf00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8ed0, count: -10 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ca8e3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e0a0400,d64,580,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da76328,9,fffffd805e0a0000,0,0,ffff80001d71ceb0) at tcp_usrreq+0xa54 sosend(fffffd805da76328,0,ffff80001d6cdd98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71ceb0,4,ffff80001d6cdd98,0,ffff80001d6cde80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71ceb0,ffff80001d6cde30,ffff80001d6cde80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cdf00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8ed0, count: -10